You've probably been there.

You're patiently waiting at a red-arrow light. You watch as all the other lights at the intersection go through a full cycle. Then another cycle. Then another.

You realize that your arrow, which is still red, is one of those lights that only changes when a pavement detector is tripped. And for reasons you may never understand, the sensor is ignoring your car.

You can't spend the rest of your life there -- for one thing, you didn't bring enough food. What should you do?

Alert reader Steve of Prior Lake asked that question on behalf of his teenage daughter. She found herself stranded in a left-turn lane on a bitter January night, then decided on a course of action:

She looked over her shoulder, saw no traffic, put on her signal and moved into the straight-through lane with a green light. A policeman pulled her over, and after hearing her explanation, gave her a ticket for a "semaphore" violation....

I am stumped by this, and since I have two other children that will be driving soon, I don't know what to tell them about how to handle this situation.

It's a tough one all around. Officers are used to hearing all manner of excuses, and "the stoplight is broken," even if it's true, can sound a little fishy. At the same time, as Lt. Randy Hofstad of the Prior Lake police notes, "it's not practical to sit at a light for three hours."

Sgt. Therese Hoffman, who works in traffic control for the Minneapolis police, said Steve's daughter made the right move. "Then she should go to court and explain it to the judge," Hoffman said, pointing out that not only do detectors sometimes malfunction, but drivers sometimes don't pull up far enough to activate them, or they pull up too far.

Hofstad didn't want to comment on any specific incidents, but he said drivers stuck at an unchanging signal would be wise to consider some rules that apply to motorcycles.

State law allows motorcycles, under certain conditions, to pass through "unchanging traffic control signals." That's because even a giant Harley with a giant rider might not weigh enough for detectors to detect. The rule applies if the light doesn't change "for an unreasonable time," and motorcyclists are required to have been at a complete stop and only proceed if doing so wouldn't create a hazard.

When a car driver claims that a light didn't change, Hofstad said, officers in his department will sometimes go back and check out the signal. He encouraged drivers who think they've encountered a faulty detector to let the city know.

Sure, why not? If you're stranded at a light, there's plenty of time to pull out a cell phone and make a call.

Transportation thoughts or questions? E-mail roadguy@startribune.com or call 612-673-4491.